U.S. patent application number 14/813418 was filed with the patent office on 2016-02-04 for axial flow compressor and gas turbine equipped with axial flow compressor.
The applicant listed for this patent is MITSUBISHI HITACHI POWER SYSTEMS, LTD.. Invention is credited to Masaru SEKIHARA, Yasuo TAKAHASHI.
Application Number | 20160032739 14/813418 |
Document ID | / |
Family ID | 54062614 |
Filed Date | 2016-02-04 |
United States Patent
Application |
20160032739 |
Kind Code |
A1 |
SEKIHARA; Masaru ; et
al. |
February 4, 2016 |
AXIAL FLOW COMPRESSOR AND GAS TURBINE EQUIPPED WITH AXIAL FLOW
COMPRESSOR
Abstract
An axial flow compressor comprising: a rotor blade and a stator
blade to intake air from an atmosphere and compress the air; a
wheel to secure the rotor blade; a casing to secure the stator
blade; wherein a wheel dovetail which is machined on an outer
circumferential surface of the wheel to have a certain angle with
respect to a rotational axis of the axial flow compressor; and a
rotor blade dovetail which is machined on an inner circumferential
side of the rotor blade to secure by being fitted to the wheel
dovetail, characterized in that: a cut surface is formed on at
least one of an upstream side and a downstream side of the rotor
blade dovetail by cutting a part of the rotor blade dovetail in a
surface form.
Inventors: |
SEKIHARA; Masaru; (Yokohama,
JP) ; TAKAHASHI; Yasuo; (Yokohama, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HITACHI POWER SYSTEMS, LTD. |
Yokohama |
|
JP |
|
|
Family ID: |
54062614 |
Appl. No.: |
14/813418 |
Filed: |
July 30, 2015 |
Current U.S.
Class: |
60/805 ;
415/208.1 |
Current CPC
Class: |
F05D 2240/35 20130101;
F01D 5/02 20130101; F02C 3/04 20130101; F05D 2260/94 20130101; F05D
2250/241 20130101; F01D 9/041 20130101; F01D 25/24 20130101; F05D
2220/32 20130101; F05D 2260/941 20130101; F01D 5/3007 20130101;
F05D 2240/301 20130101; F05D 2250/712 20130101; F05D 2250/711
20130101; F01D 5/147 20130101 |
International
Class: |
F01D 5/30 20060101
F01D005/30; F01D 25/24 20060101 F01D025/24; F01D 5/02 20060101
F01D005/02; F01D 5/14 20060101 F01D005/14; F02C 3/04 20060101
F02C003/04; F01D 9/04 20060101 F01D009/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 1, 2014 |
JP |
2014-157405 |
Claims
1. An axial flow compressor comprising: a rotor blade and a stator
blade to intake air from an atmosphere and compress the air; a
wheel to secure the rotor blade; a casing to secure the stator
blade; wherein a wheel dovetail which is machined on an outer
circumferential surface of the wheel to have a certain angle with
respect to a rotational axis of the axial flow compressor; and a
rotor blade dovetail which is machined on an inner circumferential
side of the rotor blade to secure by being fitted to the wheel
dovetail, characterized in that: a cut surface is formed on at
least one of an upstream side and a downstream side of the rotor
blade dovetail by cutting a part of the rotor blade dovetail in a
surface form.
2. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form, which is formed on at least one of the upstream side and the
downstream side of the rotor blade dovetail, is formed in a planar
shape.
3. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form, which is formed on at least one of the upstream side and the
downstream side of the rotor blade dovetail, is a spherical concave
surface.
4. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form, which is formed on at least one of the upstream side and the
downstream side of the rotor blade dovetail, is a spherical convex
surface.
5. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form, which is formed on at least one of the upstream side and the
downstream side of the rotor blade dovetail, is a curved concave
surface.
6. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form cut in a surface form, which is formed on at least one of the
upstream side and the downstream side of the rotor blade dovetail,
is a curved convex surface.
7. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form cut in a surface form, which is formed on at least one of the
upstream side and the downstream side of the rotor blade dovetail,
is a concave surface consisting of a plurality of flat
surfaces.
8. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form cut in a surface form, which is formed on at least one of the
upstream side and the downstream side of the rotor blade dovetail,
is a convex surface consisting of a plurality of flat surfaces.
9. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form, which is formed on the rotor blade dovetail, is disposed on
an inclined surface of the rotor blade dovetail, which is formed
with a curbed surface.
10. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form cut in a surface form, which is formed on the rotor blade
dovetail, is disposed on an inclined surface of the rotor blade
dovetail, which is formed with a flat surface.
11. The axial flow compressor according to claim 1, wherein the cut
surface by cutting a part of the rotor blade dovetail in a surface
form cut in a surface form, which is formed on at least one of the
upstream side and the downstream side of the rotor blade dovetail,
is formed in a range of the rotor blade dovetail, of which the
range is corresponding to a range in the wheel dovetail, in which
stress exerted from the rotor blade to the wheel dovetail is at a
certain level or higher.
12. A gas turbine comprising: an axial flow compressor according to
claim 1, which is used to intake air from the atmosphere and
compress the air; a combustor to mix the compressed air supplied
from the axial flow compressor with a fuel, and burn a mixture of
the compressed air with the fuel to generate a high-temperature
combustion gas; and a turbine which is driven by the
high-temperature combustion gas generated in the combustor to
generate a rotational power.
Description
CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese patent
application serial No. 2014-157405, filed on Aug. 1, 2014, the
content of which is hereby incorporated by reference into this
application.
TECHNICAL FIELD
[0002] The present invention relates to an axial flow compressor
that secures a rotor blade with a wheel dovetail having a certain
angle in the direction of a rotational axis, and a gas turbine
equipped with the axial flow compressor, and more particularly to
an axial flow compressor with a structure in which a rotor blade is
secured with a wheel dovetail provided so as to have a certain
angle in the direction of the rotational axis of the rotor blade
and a gas turbine that includes the axial flow compressor, a
combustor to mix compressed air supplied from the axial flow
compressor with a fuel and burn a mixture of the compressed air
with the fuel to generate a high-temperature combustion gas, and a
turbine which is driven by the high-temperature combustion gas
supplied from the combustor to generate a rotational power with the
combustion gas supplied from the combustor.
BACKGROUND ART
[0003] A gas turbine comprises mainly an axial flow compressor, a
combustor, and a turbine.
[0004] The axial flow compressor intakes an air from the atmosphere
and adiabatically compresses the air. The combustor mixes the
compressed air supplied from the axial flow compressor with a fuel,
and burns a mixture of the compressed air with the fuel to generate
a high-temperature combustion gas. When the combustion gas supplied
from the combustor is expanded, the turbine generates a rotational
power. An exhaust gas exhausted from the turbine is released to the
atmosphere.
[0005] To assure high maintainability and high structure
attenuation to reduce vibration stress, the rotor blade of the
axial flow compressor often has a rotor blade dovetail, which fits
to a groove in a dovetail formed on the outer circumferential side
of the wheel, on the inner circumferential side of a rotor blade
and is secured to the wheel dovetail.
[0006] In this fitting structure, attention must be paid to stress
exerted on the wheel dovetail and rotor blade dovetail.
[0007] One type of damage that must be considered in the dovetail
structure is fatigue damage. In a general example of fatigue
damage, when excessive stress is repeatedly exerted, a fine crack
is initiated from, for example, a metal surface, grows, and causes
breakage.
[0008] An effective countermeasure against this damage is to reduce
exerted stress. It is desirable to reduce centrifugal stress or
thermal stress by, for example, changing a shape or reducing a
thermal load.
[0009] To reduce stress exerted on a dovetail section, the
technology described in Japanese Patent Laid-open No. 2008-69781
proposes a structure in which an undercut fillet radius, for a
rotor blade dovetail, that has a multi-part profile shape is formed
at an intersection of a dovetail platform and a dovetail pressure
surface.
[0010] To reduce stress exerted on the rotor blade side, the
technology described in Japanese Patent Laid-open No. 2008-69781
proposes a structure in which a fillet is provided on the dovetail
section.
CITATION LIST
Patent Literature
[0011] {Patent Literature 1} Japanese Patent Laid-open No.
2008-69781
SUMMARY OF INVENTION
Technical Problem
[0012] As the performance of axial flow compressors has been
improved, rotor blade design to increase a per-stage load is
becoming dominant in recent years, so stress exerted on a dovetail
structure needs to be further reduced.
[0013] However, the conventional technology described in Japanese
Patent Laid-open No. 2008-69781 is not intended to reduce stress
exerted on a wheel dovetail, so a new dovetail structure is
needed.
[0014] As the per-stage load is increased, as for an angle in a
direction in which the wheel dovetail is placed, an angle with
respect to the direction of a rotational axis tends to increase,
and asymmetry of a load exerted from a rotor blade fitting to a
groove formed in a wheel dovetail provided on the outer
circumferential surface of a conical or cylindrical wheel
(asymmetry between a force with which a load exerted from the rotor
blade is exerted in the same forward direction as the rotational
direction of the rotor blade and a force exerted on the reverse
rotational direction, which is opposite to the rotational direction
of the rotor blade) tends to increase for each dovetail at both the
upstream side and the downstream side in the flow direction of a
working fluid.
[0015] As a result, local stress exerted on the wheel dovetail
becomes asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade, causing
an imbalance. This is a factor that causes high stress.
[0016] An object of the present invention is to provide an axial
flow compressor and a gas turbine equipped with the axial flow
compressor, wherein the axial flow compressor includes rotor blade
dovetails, each of which reduces high stress exerted on the rotor
blade by reducing an uneven contact with the corresponding wheel
dovetail so as to level a load that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade.
Solution to Problem
[0017] An axial flow compressor comprising: a rotor blade and a
stator blade to intake air from an atmosphere and compress the air;
a wheel to secure the rotor blade; a casing to secure the stator
blade; wherein a wheel dovetail which is machined on an outer
circumferential surface of the wheel to have a certain angle with
respect to a rotational axis of the axial flow compressor; and a
rotor blade dovetail which is machined on an inner circumferential
side of the rotor blade to secure by being fitted to the wheel
dovetail, characterized in that: a cut surface is formed on at
least one of an upstream side and a downstream side of the rotor
blade dovetail by cutting a part of the rotor blade dovetail in a
surface form.
[0018] A gas turbine of the present invention, comprising:
[0019] an axial flow compressor configured so that the
above-described axial flow compressor which is used to intake air
from the atmosphere and compress the air; a combustor to mix the
compressed air supplied from the axial flow compressor with a fuel,
and burn a mixture of the compressed air with the fuel to generate
a high-temperature combustion gas; and a turbine which is driven by
the high-temperature combustion gas generated in the combustor to
generate a rotational power.
Advantageous Effects of Invention
[0020] According to the present invention, an axial flow compressor
that includes rotor blade dovetails that reduce high stress exerted
on rotor blades by reducing an uneven contact with each wheel
dovetail so as to level a load that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade, and a gas turbine
equipped with the axial flow compressor, can be realized.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a first embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a planar
shape. The drawing at the bottom of FIG. 1 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0022] FIG. 2 partially illustrates the structure of the axial flow
compressor according to the first embodiment of the present
invention; in the structure, compressor rotor blades, each of which
has the rotor blade dovetail, are incorporated into their relevant
wheel dovetails of a compressor wheel.
[0023] FIG. 3 schematically illustrates the structure of a gas
turbine that has the axial flow compressor, having the rotor blade
dovetails, according to the first embodiment of the present
invention, a combustor, and a turbine.
[0024] FIG. 4 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a second embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
planar shape. The drawing at the bottom of FIG. 4 partially
illustrates the rotor blade dovetail in this embodiment when viewed
from above.
[0025] FIG. 5 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a third embodiment of the present invention; both the
upstream side and the downstream side of the inclined surface of
the rotor blade dovetail, the inclined surface being a curved
surface, are cut in a planar shape. The drawing at the bottom of
FIG. 5 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0026] FIG. 6 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a fourth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a concave
shape formed with a spherical surface. The drawing at the bottom of
FIG. 6 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0027] FIG. 7 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a fifth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a convex
shape formed with a spherical surface. The drawing at the bottom of
FIG. 7 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0028] FIG. 8 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a sixth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a concave
shape formed with a curved surface. The drawing at the bottom of
FIG. 8 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0029] FIG. 9 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a seventh embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a convex
shape formed with a curved surface. The drawing at the bottom of
FIG. 9 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0030] FIG. 10 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to an eighth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a concave
shape consisting of a plurality of flat surfaces. The drawing at
the bottom of FIG. 10 partially illustrates the rotor blade
dovetail in this embodiment when viewed from above.
[0031] FIG. 11 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a ninth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a curved surface, is cut in a convex
shape consisting of a plurality of flat surfaces. The drawing at
the bottom of FIG. 11 partially illustrates the rotor blade
dovetail in this embodiment when viewed from above.
[0032] FIG. 12 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a tenth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a flat surface, is cut in a planar
shape. The drawing at the bottom of FIG. 12 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0033] FIG. 13 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to an eleventh embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a flat surface, is cut in a concave
shape formed with a curved surface. The drawing at the bottom of
FIG. 13 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0034] FIG. 14 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twelfth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a flat surface, is cut in a convex shape
formed with a curved surface. The drawing at the bottom of FIG. 14
partially illustrates the rotor blade dovetail in this embodiment
when viewed from above.
[0035] FIG. 15 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirteenth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a flat surface, is cut in a concave
shape consisting of a plurality of flat surfaces. The drawing at
the bottom of FIG. 15 partially illustrates the rotor blade
dovetail in this embodiment when viewed from above.
[0036] FIG. 16 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a fourteenth embodiment of the present invention; the
upstream side of the inclined surface of the rotor blade dovetail,
the inclined surface being a flat surface, is cut in a convex shape
consisting of a plurality of flat surfaces. The drawing at the
bottom of FIG. 16 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0037] FIG. 17 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a fifteenth embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
concave shape formed with a spherical surface. The drawing at the
bottom of FIG. 17 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0038] FIG. 18 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a sixteenth embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
convex shape formed with a spherical surface. The drawing at the
bottom of FIG. 18 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0039] FIG. 19 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a seventeenth embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
concave shape formed with a curved surface. The drawing at the
bottom of FIG. 19 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0040] FIG. 20 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to an eighteenth embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
convex shape formed with a curved surface. The drawing at the
bottom of FIG. 20 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0041] FIG. 21 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a nineteenth embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
concave shape consisting of a plurality of flat surfaces. The
drawing at the bottom of FIG. 21 partially illustrates the rotor
blade dovetail in this embodiment when viewed from above.
[0042] FIG. 22 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twentieth embodiment of the present invention; the
downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a curved surface, is cut in a
convex shape consisting of a plurality of flat surfaces. The
drawing at the bottom of FIG. 22 partially illustrates the rotor
blade dovetail in this embodiment when viewed from above.
[0043] FIG. 23 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-first embodiment of the present invention;
the downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a flat surface, is cut in a
planar shape. The drawing at the bottom of FIG. 23 partially
illustrates the rotor blade dovetail in this embodiment when viewed
from above.
[0044] FIG. 24 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-second embodiment of the present invention;
the downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a flat surface, is cut in a
concave shape formed with a curved surface. The drawing at the
bottom of FIG. 24 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0045] FIG. 25 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-third embodiment of the present invention;
the downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a flat surface, is cut in a
convex shape formed with a curved surface. The drawing at the
bottom of FIG. 25 partially illustrates the rotor blade dovetail in
this embodiment when viewed from above.
[0046] FIG. 26 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-fourth embodiment of the present invention;
the downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a flat surface, is cut in a
concave shape consisting of a plurality of flat surfaces. The
drawing at the bottom of FIG. 26 partially illustrates the rotor
blade dovetail in this embodiment when viewed from above.
[0047] FIG. 27 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-fifth embodiment of the present invention;
the downstream side of the inclined surface of the rotor blade
dovetail, the inclined surface being a flat surface, is cut in a
convex shape consisting of a plurality of flat surfaces. The
drawing at the bottom of FIG. 27 partially illustrates the rotor
blade dovetail in this embodiment when viewed from above.
[0048] FIG. 28 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-sixth embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
curved surface, are cut in a concave shape formed with a spherical
surface. The drawing at the bottom of FIG. 28 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0049] FIG. 29 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-seventh embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
curved surface, are cut in a convex shape formed with a spherical
surface. The drawing at the bottom of FIG. 29 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0050] FIG. 30 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-eighth embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
curved surface, are cut in a concave shape formed with a spherical
surface. The drawing at the bottom of FIG. 30 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0051] FIG. 31 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a twenty-ninth embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
curved surface, are cut in a convex shape formed with a curved
surface. The drawing at the bottom of FIG. 31 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0052] FIG. 32 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirtieth embodiment of the present invention; both
the upstream side and the downstream side of the inclined surface
of the rotor blade dovetail, the inclined surface being a curved
surface, are cut in a concave shape consisting of a plurality of
flat surfaces. The drawing at the bottom of FIG. 32 partially
illustrates the rotor blade dovetail in this embodiment when viewed
from above.
[0053] FIG. 33 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirty-first embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
curved surface, are cut in a convex shape consisting of a plurality
of flat surfaces. The drawing at the bottom of FIG. 33 partially
illustrates the rotor blade dovetail in this embodiment when viewed
from above.
[0054] FIG. 34 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirty-second embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
flat surface, are cut in a planner shape. The drawing at the bottom
of FIG. 34 partially illustrates the rotor blade dovetail in this
embodiment when viewed from above.
[0055] FIG. 35 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirty-third embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
flat surface, are cut in a concave shape formed with a curved
surface. The drawing at the bottom of FIG. 35 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0056] FIG. 36 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirty-fourth embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
flat surface, are cut in a convex shape formed with a curved
surface. The drawing at the bottom of FIG. 36 partially illustrates
the rotor blade dovetail in this embodiment when viewed from
above.
[0057] FIG. 37 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirty-fifth embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
flat surface, are cut in a concave shape consisting of a plurality
of flat surfaces. The drawing at the bottom of FIG. 37 partially
illustrates the rotor blade dovetail in this embodiment when viewed
from above.
[0058] FIG. 38 partially illustrates a rotor blade dovetail that
secures a rotor blade included in an axial flow compressor
according to a thirty-sixth embodiment of the present invention;
both the upstream side and the downstream side of the inclined
surface of the rotor blade dovetail, the inclined surface being a
flat surface, are cut in a convex shape consisting of a plurality
of flat surfaces. The drawing at the bottom of FIG. 38 partially
illustrates the rotor blade dovetail in this embodiment when viewed
from above.
DESCRIPTION OF EMBODIMENTS
[0059] The axial flow compressor according to the present invention
and a gas turbine equipped with the axial flow compressor will be
described below with reference to the drawings.
Embodiment 1
[0060] A first embodiment of the axial flow compressor according to
the present invention will be described with reference to FIGS. 1
to 3.
[0061] FIG. 1 partially illustrates a rotor blade dovetail 5 that
secures a rotor blade 4 included in the axial flow compressor
according to the first embodiment of the present invention; on the
upstream side of the inclined surface 7 of the rotor blade dovetail
5, the inclined surface 7 being a curved surface, a flat surface 6,
which is a cut flat surface, is formed.
[0062] The drawing at the bottom of FIG. 1 partially illustrates
the rotor blade dovetail 5 in this embodiment when viewed from
above.
[0063] The rotor blade dovetail 5 that secures the rotor blade 4
included in the axial flow compressor, illustrated in FIG. 1,
according to the first embodiment has the flat surface 6, which is
a cut surface formed by cutting part of the rotor blade dovetail 5
on the upstream side in the flow direction of a working fluid
toward a maximum width part 7c of the inclined surface 7, on an end
surface 5a of the rotor blade dovetail 5 on the upstream side of
the inclined surface 7, which is a curved surface.
[0064] The rotor blade dovetail 5 is provided at the bottom of each
of a plurality of rotor blades 4, which are part of the axial flow
compressor 1 according to this embodiment. Since the rotor blade 4
is placed at a certain angle with respect to the direction of the
rotational axis as illustrated in FIG. 2, the rotor blade dovetail
5 is also placed at a certain angle with respect to the direction
of the rotational axis. A plurality of wheel dovetails 14 are
placed on the outer surface of a compressor wheel 8, which is a
rotating body of the axial flow compressor 1, at a certain angle
with respect to the direction of the rotational axis of the
rotating body. One rotor blade dovetail 5 is fitted into the inside
of each wheel dovetail 14, forming the rotating body of the axial
flow compressor 1.
[0065] As illustrated in FIG. 3, the axial flow compressor 1
according to the first embodiment comprising a rotor blade 4 and a
stator blade 18 to intake air from an atmosphere and compress the
air as a working fluid, a wheel 8 that secures the rotor blade 4,
and a casing that secures the stator blade 18.
[0066] As illustrated in FIG. 1, the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor
according to the first embodiment has the flat surface 6, which is
a cut surface formed by cutting part of the rotor blade dovetail 5
on the upstream side in the flow direction of a working fluid
toward the maximum width part 7c of the inclined surface 7, on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7, which is a curved surface.
[0067] Since this embodiment uses a structure in which the flat
surface 6, which is a cut surface, is formed on the end surface 5a
of the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface, in the flow direction of a
working fluid, an uneven contact with the wheel dovetail 14 can be
reduced and a load exerted from the rotor blade 4 can thereby be
evened; the load would otherwise become asymmetric between the
forward direction and reverse direction of the rotational direction
of the rotor blade 4. As a result, high stress exerted on the rotor
blade 4 can be reduced.
[0068] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 2
[0069] The rotor blade dovetail 5 in the axial flow compressor 1
according to a second embodiment of the present invention will be
described with reference to FIG. 4.
[0070] The basic structure of the axial flow compressor 1 in the
second embodiment illustrated in FIG. 4 is the same as in the first
embodiment of the axial flow compressor 1 according to the present
invention illustrated in FIGS. 1 to 3, so descriptions of
structures common to these two embodiments will be omitted and only
differences between them will be described.
[0071] FIG. 4 partially illustrates the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor 1
according to the second embodiment of the present invention; on an
end surface 5b of the rotor blade dovetail 5 on the downstream side
of the inclined surface 7, which is a curved surface, a flat
surface 6b is formed, which is a cut surface formed by cutting part
of the rotor blade dovetail 5 on the downstream side in the flow
direction of a working fluid toward the maximum width part 7c of
the inclined surface 7.
[0072] With the rotor blade dovetail 5 in the axial flow compressor
1 in this embodiment, in which the flat surface 6b, which is a cut
surface, is formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 7, almost
the same effect as with the rotor blade dovetail 5 in the axial
flow compressor 1 in the first embodiment can be obtained depending
on the design specifications; in the first embodiment, the flat
surface 6, which is a cut surface, is formed on the end surface 5a
of the rotor blade dovetail 5 on the upstream side of the inclined
surface 7.
[0073] This embodiment described above uses a structure in which
the flat surface 6b, which is a cut surface, is formed on the end
surface 5b of the rotor blade dovetail 5 on the downstream side of
the inclined surface 7, which is a curved surface, so a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0074] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 3
[0075] The rotor blade dovetail 5 in the axial flow compressor 1
according to a third embodiment of the present invention will be
described with reference to FIG. 5. The rotor blade dovetail 5 of
the axial flow compressor 1 in the third embodiment illustrated in
FIG. 5 has the same basic structure as the rotor blade dovetail 5
in the first embodiment of the axial flow compressor 1 according to
the present invention illustrated in FIGS. 1 to 3, so descriptions
of structures common to these two embodiments will be omitted and
only differences between them will be described.
[0076] The rotor blade dovetails in the axial flow compressors in a
third embodiment and later in the present invention also have the
same basic structure as the rotor blade dovetail 5 in the first
embodiment of the axial flow compressor 1 according to the present
invention illustrated in FIGS. 1 to 3, so descriptions of
structures common to the relevant embodiment and the first
embodiment will be omitted and only differences between them will
be described.
[0077] FIG. 5 partially illustrates the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor
according to the third embodiment of the present invention; on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7, which is a curved surface, the flat
surface 6 is formed, which is a cut surface formed by cutting part
of the rotor blade dovetail 5 on the upstream side in the flow
direction of a working fluid toward the maximum width part 7c of
the inclined surface 7; on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 7 as
well, which is a curved surface, the flat surface 6b is formed,
which is a cut surface formed by cutting part of the rotor blade
dovetail 5 toward the maximum width part 7c of the inclined surface
7.
[0078] This embodiment described above uses a structure in which
the flat surface 6, which is a cut surface, is formed on the end
surface 5a of the rotor blade dovetail 5 on the upstream side of
the inclined surface 7, which is a curved surface, and the flat
surface 6b, which is a cut surface, is also formed on the end
surface 5b of the rotor blade dovetail 5 on the downstream side of
the inclined surface 7, so an uneven contact with the wheel
dovetail 14 can be greatly reduced on both the upstream side and
downstream side of the rotor blade dovetail 5. Therefore, a load
exerted from the rotor blade 4 can be further evened; the load
would otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0079] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 4
[0080] The rotor blade dovetail 5 in the axial flow compressor
according to a fourth embodiment of the present invention will be
described with reference to FIG. 6.
[0081] FIG. 6 partially illustrates the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor
according to the fourth embodiment of the present invention; on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7, which is a curved surface, a spherical
concave surface 15 is formed, which is a cut surface.
[0082] This embodiment described above uses a structure in which
the spherical concave surface 15, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface. Therefore, a load exerted
from the rotor blade 4 can be evened; the load would otherwise
become asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade 4. As a
result, high stress exerted on the rotor blade 4 can be
reduced.
[0083] With the rotor blade dovetail 5, illustrated in FIG. 6, in
the axial flow compressor in this embodiment, the cut surface is
the spherical concave surface 15 instead of the flat surface 6 in
the first embodiment. Therefore, the rotor blade dovetail 5 in the
axial flow compressor in this embodiment is lighter than the rotor
blade dovetail 5 in the axial flow compressor in the first
embodiment by the amount of formation of the spherical concave
surface 15, so an advantage of reducing stress exerted on the rotor
blade dovetail 5 can be obtained.
[0084] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 5
[0085] The rotor blade dovetail 5 in the axial flow compressor
according to a fifth embodiment of the present invention will be
described with reference to FIG. 7.
[0086] FIG. 7 partially illustrates the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor
according to the fifth embodiment of the present invention; on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7, which is a curved surface, a spherical
convex surface 16 is formed, which is a cut surface.
[0087] This embodiment described above uses a structure in which
the spherical convex surface 16, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface. Therefore, a load exerted
from the rotor blade 4 can be evened; the load would otherwise
become asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade 4. As a
result, high stress exerted on the rotor blade 4 can be
reduced.
[0088] With the rotor blade dovetail 5, illustrated in FIG. 7, in
the axial flow compressor in this embodiment, the cut surface is
the spherical convex surface 16. This is preferable for the wheel
dovetail 14 in terms of strength.
[0089] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 6
[0090] The rotor blade dovetail 5 in the axial flow compressor 1
according to a sixth embodiment of the present invention will be
described with reference to FIG. 8.
[0091] FIG. 8 partially illustrates the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor
according to the sixth embodiment of the present invention; on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7, which is a curved surface, a curved
concave surface 9 is formed, which is a cut surface.
[0092] This embodiment described above uses a structure in which
the curved concave surface 9, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface. Therefore, a load exerted
from the rotor blade 4 can be evened; the load would otherwise
become asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade 4. As a
result, high stress exerted on the rotor blade 4 can be
reduced.
[0093] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved concave surface
9, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved concave surface 9. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the curved concave surface 9 is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15.
[0094] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 7
[0095] The rotor blade dovetail 5 in the axial flow compressor
according to a seventh embodiment of the present invention will be
described with reference to FIG. 9.
[0096] FIG. 9 partially illustrates the rotor blade dovetail 5 that
secures the rotor blade 4 included in the axial flow compressor
according to the seventh embodiment of the present invention; on
the end surface 5a of the rotor blade dovetail 5 on the upstream
side of the inclined surface 7, which is a curved surface, a curved
convex surface 10 is formed, which is a cut surface.
[0097] This embodiment described above uses a structure in which
the curved convex surface 10, which is a cut surface, is formed on
the end surface 5a of the rotor blade dovetail 5 on the upstream
side of the inclined surface 7, which is a curved surface.
Therefore, a load exerted from the rotor blade 4 can be evened; the
load would otherwise become asymmetric between the forward
direction and reverse direction of the rotational direction of the
rotor blade 4. As a result, high stress exerted on the rotor blade
4 can be reduced.
[0098] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved convex surface
10, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved convex surface 10. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the curved convex surface 10 is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16.
[0099] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 8
[0100] The rotor blade dovetail 5 in the axial flow compressor
according to an eighth embodiment of the present invention will be
described with reference to FIG. 10.
[0101] FIG. 10 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the eighth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, a concave surface 12 consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0102] This embodiment described above uses a structure in which
the concave surface 12 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 7c of the inclined
surface 7, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 7, which is
a curved surface. Therefore, a load exerted from the rotor blade 4
can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0103] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the concave surface 12
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
concave surface 12. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the concave surface 12 consisting of a plurality of flat surfaces
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15 or
curved concave surface 9.
[0104] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 9
[0105] The rotor blade dovetail 5 in the axial flow compressor
according to a ninth embodiment of the present invention will be
described with reference to FIG. 11.
[0106] FIG. 11 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the ninth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, a convex surface 13 consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0107] This embodiment described above uses a structure in which
the convex surface 13 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 7c of the inclined
surface 7, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 7, which is
a curved surface. Therefore, a load exerted from the rotor blade 4
can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0108] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the convex surface 13
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
convex surface 13. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the convex surface 13 consisting of a plurality of flat surfaces is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16 or curved
convex surface 10.
[0109] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 10
[0110] The rotor blade dovetail 5 in the axial flow compressor
according to a tenth embodiment of the present invention will be
described with reference to FIG. 12.
[0111] FIG. 12 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the tenth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of an inclined surface 11, which is a flat
surface, the flat surface 6, which is a cut surface, is formed.
[0112] This embodiment described above uses a structure in which
the flat surface 6, which is a cut surface formed by cutting part
of the rotor blade dovetail 5 on the upstream side in the flow
direction of a working fluid toward the maximum width part 11c of
the inclined surface 11, is formed on the end surface 5a of the
rotor blade dovetail 5 on the upstream side of the inclined surface
11, which is a flat surface. Therefore, a load exerted from the
rotor blade 4 can be evened; the load would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade 4. As a result, high
stress exerted on the rotor blade 4 can be reduced.
[0113] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 11
[0114] The rotor blade dovetail 5 in the axial flow compressor
according to an eleventh embodiment of the present invention will
be described with reference to FIG. 13.
[0115] FIG. 13 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the eleventh embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a cut
surface, the curved concave surface 9 is formed, which is a cut
surface.
[0116] This embodiment described above uses a structure in which
the curved concave surface 9, which is a cut surface, is formed on
the end surface 5a of the rotor blade dovetail 5 on the upstream
side of the inclined surface 11, which is a flat surface.
Therefore, a load exerted from the rotor blade 4 can be evened; the
load would otherwise become asymmetric between the forward
direction and reverse direction of the rotational direction of the
rotor blade 4. As a result, high stress exerted on the rotor blade
4 can be reduced.
[0117] This embodiment described above uses a structure in which
the curved concave surface 9, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
11c of the inclined surface 11, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 11. Therefore, a load exerted from the rotor blade 4 can be
evened; the load would otherwise become asymmetric between the
forward direction and reverse direction of the rotational direction
of the rotor blade 4. As a result, high stress exerted on the rotor
blade 4 can be reduced.
[0118] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved concave surface
9, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved concave surface 9. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the curved concave surface 9 is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15.
[0119] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0120] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 12
[0121] The rotor blade dovetail 5 in the axial flow compressor
according to a twelfth embodiment of the present invention will be
described with reference to FIG. 14.
[0122] FIG. 14 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twelfth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a cut
surface, the curved convex surface 10 is formed, which is a cut
surface.
[0123] This embodiment described above uses a structure in which
the curved convex surface 10, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
lic of the inclined surface 11, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 11, which is a curved surface. Therefore, a load exerted
from the rotor blade 4 can be evened; the load would otherwise
become asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade 4. As a
result, high stress exerted on the rotor blade 4 can be
reduced.
[0124] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved convex surface
10, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved convex surface 10. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the curved convex surface 10 is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16.
[0125] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0126] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 13
[0127] The rotor blade dovetail 5 in the axial flow compressor
according to a thirteenth embodiment of the present invention will
be described with reference to FIG. 15.
[0128] FIG. 15 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirteenth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the concave surface 12 consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0129] This embodiment described above uses a structure in which
the concave surface 12 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 11c of the inclined
surface 11, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 11, which
is a flat surface. Therefore, a load exerted from the rotor blade 4
can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0130] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the concave surface 12
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
concave surface 12. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the concave surface 12 consisting of a plurality of flat surfaces
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15.
[0131] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0132] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 14
[0133] The rotor blade dovetail 5 in the axial flow compressor
according to a fourteenth embodiment of the present invention will
be described with reference to FIG. 16.
[0134] FIG. 16 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the fourteenth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the concave surface 13 consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0135] This embodiment described above uses a structure in which
the convex surface 13 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 11c of the inclined
surface 11, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 11, which
is a flat surface. Therefore, a load exerted from the rotor blade 4
can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0136] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the convex surface 13
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
convex surface 13. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the convex surface 13 consisting of a plurality of flat surfaces is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16.
[0137] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0138] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 15
[0139] The rotor blade dovetail 5 in the axial flow compressor
according to a fifteenth embodiment of the present invention will
be described with reference to FIG. 17.
[0140] FIG. 17 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the fifteenth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, a curved concave surface 15b is formed, which is a cut
surface.
[0141] This embodiment described above uses a structure in which
the curved concave surface 15b, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the downstream side
in the flow direction of a working fluid toward the maximum width
part 7c of the inclined surface 7, is formed on the end surface 5b
of the rotor blade dovetail 5 on the downstream side of the
inclined surface 7, which is a curved surface. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0142] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved concave surface
15b, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the spherical concave surface 15b. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the spherical concave surface 15b
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15.
[0143] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 16
[0144] The rotor blade dovetail 5 in the axial flow compressor
according to a sixteenth embodiment of the present invention will
be described with reference to FIG. 18.
[0145] FIG. 18 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the sixteenth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, a curved convex surface 16b is formed, which is a cut
surface.
[0146] This embodiment described above uses a structure in which
the curved convex surface 16b, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the downstream side
in the flow direction of a working fluid toward the maximum width
part 7c of the inclined surface 7, is formed on the end surface 5b
of the rotor blade dovetail 5 on the downstream side of the
inclined surface 7, which is a curved surface. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0147] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved convex surface
16b, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the spherical convex surface 16b. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the spherical convex surface 16b
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16.
[0148] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 17
[0149] The rotor blade dovetail 5 in the axial flow compressor
according to a seventeenth embodiment of the present invention will
be described with reference to FIG. 19.
[0150] FIG. 19 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the seventeenth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, a curved concave surface 9b is formed, which is a cut
surface.
[0151] This embodiment described above uses a structure in which
the curved concave surface 9b, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the downstream side
in the flow direction of a working fluid toward the maximum width
part 7c of the inclined surface 7, is formed on the end surface 5b
of the rotor blade dovetail 5 on the downstream side of the
inclined surface 7, which is a curved surface. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0152] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved concave surface
9b, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved concave surface 9b. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the curved concave surface 9b is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15.
[0153] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 18
[0154] The rotor blade dovetail 5 in the axial flow compressor
according to an eighteenth embodiment of the present invention will
be described with reference to FIG. 20.
[0155] FIG. 20 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the eighteenth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, a curved convex surface 10b is formed, which is a cut
surface.
[0156] This embodiment described above uses a structure in which
the curved convex surface 10b, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the downstream side
in the flow direction of a working fluid toward the maximum width
part 7c of the inclined surface 7, is formed on the end surface 5b
of the rotor blade dovetail 5 on the downstream side of the
inclined surface 7, which is a curved surface. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0157] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the curved convex surface
10b, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved convex surface 10b. This is
advantageous in that stress exerted on the rotor blade dovetail 5
can be reduced. Another advantage obtained by forming a cut surface
of the rotor blade dovetail 5 in the curved convex surface 10b is
that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16.
[0158] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 19
[0159] The rotor blade dovetail 5 in the axial flow compressor
according to a nineteenth embodiment of the present invention will
be described with reference to FIG. 21.
[0160] FIG. 21 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the nineteenth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, a concave surface 12b consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0161] This embodiment described above uses a structure in which
the concave surface 12b consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of a
working fluid toward the maximum width part 7c of the inclined
surface 7, is formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 7, which
is a curved surface. Therefore, a load exerted from the rotor blade
4 can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0162] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the concave surface 12b
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
concave surface 12b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the concave surface 12b consisting of a plurality of flat surfaces
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15 or
curved concave surface 9.
[0163] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 20
[0164] The rotor blade dovetail 5 in the axial flow compressor
according to a twentieth embodiment of the present invention will
be described with reference to FIG. 22.
[0165] FIG. 22 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor 1 according to the twentieth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, a convex surface 13b consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0166] This embodiment described above uses a structure in which
the convex surface 13b consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of a
working fluid toward the maximum width part 7c of the inclined
surface 7, is formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 7, which
is a curved surface. Therefore, a load exerted from the rotor blade
4 can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0167] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the convex surface 13b
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
convex surface 13b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the convex surface 13b consisting of a plurality of flat surfaces
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16 or curved
convex surface 10.
[0168] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 21
[0169] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-first embodiment of the present invention
will be described with reference to FIG. 23.
[0170] FIG. 23 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-first embodiment of the present
invention; on an end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 11, which is a flat
surface, the flat surface 6b is formed, which is a cut surface.
[0171] This embodiment described above uses a structure in which
the flat surface 6b, which is a cut surface formed by cutting part
of the rotor blade dovetail 5 on the downstream side in the flow
direction of a working fluid toward the maximum width part 11c of
the inclined surface 11, is formed on the end surface 5b of the
rotor blade dovetail 5 on the upstream side of the inclined surface
11, which is a flat surface. Therefore, a load exerted from the
rotor blade 4 can be evened; the load would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade 4. As a result, high
stress exerted on the rotor blade 4 can be reduced.
[0172] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0173] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 22
[0174] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-second embodiment of the present invention
will be described with reference to FIG. 24.
[0175] FIG. 24 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor 1 according to the twenty-second embodiment of the
present invention; on an end surface 5b of the rotor blade dovetail
5 on the downstream side of the inclined surface 11, which is a
flat surface, the curved concave surface 9b is formed, which is a
cut surface.
[0176] This embodiment described above uses a structure in which
the curved concave surface 9b, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the downstream side
in the flow direction of a working fluid toward the maximum width
part 11c of the inclined surface 11, is formed on the end surface
5b of the rotor blade dovetail 5 on the downstream side of the
inclined surface 11, which is a flat surface. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0177] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0178] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 23
[0179] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-third embodiment of the present invention
will be described with reference to FIG. 25.
[0180] FIG. 25 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-third embodiment of the present
invention; on an end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 11, which is a flat
surface, the curved convex surface 10b is formed, which is a cut
surface.
[0181] This embodiment described above uses a structure in which
the curved convex surface 10b, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the downstream side
in the flow direction of a working fluid toward the maximum width
part 11c of the inclined surface 11, is formed on the end surface
5b of the rotor blade dovetail 5 on the downstream side of the
inclined surface 11, which is a flat surface. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0182] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0183] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 24
[0184] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-fourth embodiment of the present invention
will be described with reference to FIG. 26.
[0185] FIG. 26 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-fourth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 11, which is a flat
surface, the concave surface 12b consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0186] This embodiment described above uses a structure in which
the concave surface 12b consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of a
working fluid toward the maximum width part 11c of the inclined
surface 11, is formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 11, which
is a flat surface. Therefore, a load exerted from the rotor blade 4
can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0187] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the concave surface 12b
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
concave surface 12b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the concave surface 12b consisting of a plurality of flat surfaces
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical concave surface 15 or
curved concave surface 9.
[0188] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0189] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 25
[0190] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-fifth embodiment of the present invention
will be described with reference to FIG. 27.
[0191] FIG. 27 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-fifth embodiment of the present
invention; on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 11, which is a flat
surface, the concave surface 13b consisting of a plurality of flat
surfaces, each being a cut surface, is formed.
[0192] This embodiment described above uses a structure in which
the convex surface 13b consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of a
working fluid toward the maximum width part 11c of the inclined
surface 11, is formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 11, which
is a flat surface. Therefore, a load exerted from the rotor blade 4
can be evened; the load would otherwise become asymmetric between
the forward direction and reverse direction of the rotational
direction of the rotor blade 4. As a result, high stress exerted on
the rotor blade 4 can be reduced.
[0193] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the cut surface is the convex surface 13b
consisting of a plurality of flat surfaces, so the weight of the
rotor blade dovetail 5 is reduced by the amount of formation of the
convex surface 13b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced. Another advantage
obtained by forming a cut surface of the rotor blade dovetail 5 in
the convex surface 13b consisting of a plurality of flat surfaces
is that machining is easier than when forming a cut surface of the
rotor blade dovetail 5 in the spherical convex surface 16 or curved
convex surface 10.
[0194] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0195] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 26
[0196] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-sixth embodiment of the present invention
will be described with reference to FIG. 28.
[0197] FIG. 28 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-sixth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, the spherical concave surface 15 is formed, which is a cut
surface; on the end surface 5b of the rotor blade dovetail 5 on the
downstream side of the inclined surface 7, which is a curved
surface, the spherical concave surface 15b is formed, which is a
cut surface.
[0198] This embodiment described above uses a structure in which
the spherical concave surface 15, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface, and the spherical concave
surface 15b, which is a cut surface formed by cutting part of the
rotor blade dovetail 5 on the downstream side in the flow direction
of the working fluid toward the maximum width part 7c of the
inclined surface 7, is also formed on the end surface 5b of the
rotor blade dovetail 5 on the downstream side of the inclined
surface 7. Therefore, a load exerted from the rotor blade 4 can be
evened; the load would otherwise become asymmetric between the
forward direction and reverse direction of the rotational direction
of the rotor blade 4. As a result, high stress exerted on the rotor
blade 4 can be reduced.
[0199] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the spherical concave surface 15 and spherical
concave surface 15b are respectively formed as cut surfaces on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the spherical concave surface 15 and
spherical concave surface 15b. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0200] This embodiment described above uses a structure in which
the spherical concave surface 15, which is a cut surface, is formed
on the end surface 5a of the rotor blade dovetail 5 on the upstream
side of the inclined surface 7, which is a curved surface, and the
spherical concave surface 15b, which is a cut surface formed, is
also formed on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, so an uneven contact with the wheel dovetail 14 can be
greatly reduced on both the upstream side and downstream side of
the rotor blade dovetail 5. Therefore, a load exerted from the
rotor blade 4 can be further evened; the load would otherwise
become asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade 4. As a
result, high stress exerted on the rotor blade 4 can be
reduced.
[0201] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the spherical concave surface 15 and spherical
concave surface 15b are respectively formed as cut surfaces on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the spherical concave surface 15 and
spherical concave surface 15b. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0202] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 27
[0203] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-seventh embodiment of the present invention
will be described with reference to FIG. 29.
[0204] FIG. 29 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-seventh embodiment of the
present invention; on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 7, which is
a curved surface, the spherical convex surface 16 is formed, which
is a cut surface; on the end surface 5b of the rotor blade dovetail
5 on the downstream side of the inclined surface 7, which is a
curved surface, the spherical convex surface 16b is formed, which
is a cut surface.
[0205] This embodiment described above uses a structure in which
the spherical convex surface 16, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface, and the spherical convex
surface 16b, which is a cut surface formed by cutting part of the
rotor blade dovetail 5 on the downstream side in the flow direction
of the working fluid toward the maximum width part 7c of the
inclined surface 7, is also formed on the end surface 5b of the
rotor blade dovetail 5 on the downstream side of the inclined
surface 7. Therefore, a load exerted from the rotor blade 4 can be
evened; the load would otherwise become asymmetric between the
forward direction and reverse direction of the rotational direction
of the rotor blade 4. As a result, high stress exerted on the rotor
blade 4 can be reduced.
[0206] This embodiment described above uses a structure in which
the spherical convex surface 16, which is a cut surface, is formed
on the end surface 5a of the rotor blade dovetail 5 on the upstream
side of the inclined surface 7, which is a curved surface, and the
spherical convex surface 16b, which is a cut surface formed, is
also formed on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 7, which is a curved
surface, so an uneven contact with the wheel dovetail 14 can be
greatly reduced on both the upstream side and downstream side of
the rotor blade dovetail 5. Therefore, a load exerted from the
rotor blade 4 can be further evened; the load would otherwise
become asymmetric between the forward direction and reverse
direction of the rotational direction of the rotor blade 4. As a
result, high stress exerted on the rotor blade 4 can be
reduced.
[0207] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the spherical convex surface 16 and spherical
convex surface 16b are respectively formed as cut surfaces on the
end surface 5a of the rotor blade dovetail 5 on the upstream side
of the inclined surface 7 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the spherical convex surface 16 and
spherical convex surface 16b. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0208] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 28
[0209] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-eighth embodiment of the present invention
will be described with reference to FIG. 30.
[0210] FIG. 30 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-eighth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, the curved concave surface 9 is formed, which is a cut
surface; on the end surface 5b of the rotor blade dovetail 5 on the
downstream side of the inclined surface 7, which is a curved
surface, the curved concave surface 9b is formed, which is a cut
surface.
[0211] This embodiment described above uses a structure in which
the curved concave surface 9, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface, and the curved concave
surface 9b, which is a cut surface formed by cutting part of the
rotor blade dovetail 5 on the downstream side in the flow direction
of the working fluid toward the maximum width part 7c of the
inclined surface 7, is also formed on the end surface 5b of the
rotor blade dovetail 5 on the downstream side of the inclined
surface 7. Therefore, a load exerted from the rotor blade 4 can be
evened; the load would otherwise become asymmetric between the
forward direction and reverse direction of the rotational direction
of the rotor blade 4. As a result, high stress exerted on the rotor
blade 4 can be reduced.
[0212] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the curved concave surface 9 and curved concave
surface 9b are respectively formed as cut surfaces on the end
surface 5a of the rotor blade dovetail 5 on the upstream side of
the inclined surface 7 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved concave surface 9 and curved
concave surface 9b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced.
[0213] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 29
[0214] The rotor blade dovetail 5 in the axial flow compressor
according to a twenty-ninth embodiment of the present invention
will be described with reference to FIG. 31.
[0215] FIG. 31 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the twenty-ninth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, the curved convex surface 10 is formed, which is a cut
surface; on the end surface 5b of the rotor blade dovetail 5 on the
downstream side of the inclined surface 7, which is a curved
surface, the curved convex surface 10b is formed, which is a cut
surface.
[0216] This embodiment described above uses a structure in which
the curved convex surface 10, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
7c of the inclined surface 7, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 7, which is a curved surface, and the curved convex surface
10b, which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of
the working fluid toward the maximum width part 7c of the inclined
surface 7, is also formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 7.
Therefore, a load exerted from the rotor blade 4 can be evened; the
load would otherwise become asymmetric between the forward
direction and reverse direction of the rotational direction of the
rotor blade 4. As a result, high stress exerted on the rotor blade
4 can be reduced.
[0217] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the curved convex surface 10 and curved convex
surface 10b are respectively formed as cut surfaces on the end
surface 5a of the rotor blade dovetail 5 on the upstream side of
the inclined surface 7 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved convex surface 10 and curved
convex surface 10b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced.
[0218] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 30
[0219] The rotor blade dovetail 5 in the axial flow compressor
according to a thirtieth embodiment of the present invention will
be described with reference to FIG. 32.
[0220] FIG. 32 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirtieth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, the concave surface 12 consisting of a plurality of flat
surfaces, each being a cut surface, is formed; on the end surface
5b of the rotor blade dovetail 5 on the downstream side of the
inclined surface 7, which is a curved surface, the concave surface
12b consisting of a plurality of flat surfaces, each being a cut
surface, is formed.
[0221] This embodiment described above uses a structure in which
the concave surface 12 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 7c of the inclined
surface 7, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 7, which is
a curved surface, and the concave surface 12b consisting of a
plurality of flat surfaces, each of which is a cut surface formed
by cutting part of the rotor blade dovetail 5 on the downstream
side in the flow direction of the working fluid toward the maximum
width part 7c of the inclined surface 7, is also formed on the end
surface 5b of the rotor blade dovetail 5 on the downstream side of
the inclined surface 7. Therefore, a load exerted from the rotor
blade 4 can be evened; the load would otherwise become asymmetric
between the forward direction and reverse direction of the
rotational direction of the rotor blade 4. As a result, high stress
exerted on the rotor blade 4 can be reduced.
[0222] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the concave surface 12 and concave surface 12b
consisting of a plurality of flat surfaces are respectively formed
as cut surfaces on the end surface 5a of the rotor blade dovetail 5
on the upstream side of the inclined surface 7 and the end surface
5b on its downstream side, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the concave
surface 12 and concave surface 12b. This is advantageous in that
stress exerted on the rotor blade dovetail 5 can be reduced.
[0223] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 31
[0224] The rotor blade dovetail 5 in the axial flow compressor
according to a thirty-first embodiment of the present invention
will be described with reference to FIG. 33.
[0225] FIG. 33 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirty-first embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 7, which is a curved
surface, the convex surface 13 consisting of a plurality of flat
surfaces, each being a cut surface, is formed; on the end surface
5b of the rotor blade dovetail 5 on the downstream side of the
inclined surface 7, which is a curved surface, the convex surface
13b consisting of a plurality of flat surfaces, each being a cut
surface, is formed.
[0226] This embodiment described above uses a structure in which
the convex surface 13 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 7c of the inclined
surface 7, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 7, which is
a curved surface, and the convex surface 13b consisting of a
plurality of flat surfaces, each of which is a cut surface formed
by cutting part of the rotor blade dovetail 5 on the downstream
side in the flow direction of the working fluid toward the maximum
width part 7c of the inclined surface 7, is also formed on the end
surface 5b of the rotor blade dovetail 5 on the downstream side of
the inclined surface 7. Therefore, a load exerted from the rotor
blade 4 can be evened; the load would otherwise become asymmetric
between the forward direction and reverse direction of the
rotational direction of the rotor blade 4. As a result, high stress
exerted on the rotor blade 4 can be reduced.
[0227] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the convex surface 13 and convex surface 13b
consisting of a plurality of flat surfaces are respectively formed
as cut surfaces on the end surface 5a of the rotor blade dovetail 5
on the upstream side of the inclined surface 7 and the end surface
5b on its downstream side, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the convex
surface 13 and convex surface 13b. This is advantageous in that
stress exerted on the rotor blade dovetail 5 can be reduced.
[0228] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 32
[0229] The rotor blade dovetail 5 in the axial flow compressor
according to a thirty-second embodiment of the present invention
will be described with reference to FIG. 34.
[0230] FIG. 34 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirty-second embodiment of the present
invention; on an end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the flat surface 6 is formed, which is a cut surface; on
an end surface 5b of the rotor blade dovetail 5 on the downstream
side of the inclined surface 11, which is a flat surface, the flat
surface 6b is formed, which is a cut surface.
[0231] This embodiment described above uses a structure in which
the flat surface 6, which is a cut surface formed by cutting part
of the rotor blade dovetail 5 on the upstream side in the flow
direction of a working fluid toward the maximum width part 11c of
the inclined surface 11, is formed on the end surface 5a of the
rotor blade dovetail 5 on the upstream side of the inclined surface
11, which is a flat surface, and the flat surface 6b, which is a
cut surface formed by cutting part of the rotor blade dovetail 5 on
the downstream side in the flow direction of the working fluid
toward the maximum width part 11c of the inclined surface 11, is
also formed on the end surface 5b of the rotor blade dovetail 5 on
the downstream side of the inclined surface 11. Therefore, a load
exerted from the rotor blade 4 can be evened; the load would
otherwise become asymmetric between the forward direction and
reverse direction of the rotational direction of the rotor blade 4.
As a result, high stress exerted on the rotor blade 4 can be
reduced.
[0232] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the flat surface 6 and flat surface 6b are
respectively formed as cut surfaces on the end surface 5a of the
rotor blade dovetail 5 on the upstream side of the inclined surface
11 and the end surface 5b on its downstream side, so the weight of
the rotor blade dovetail 5 is reduced by the amount of formation of
the flat surface 6 and flat surface 6b. This is advantageous in
that stress exerted on the rotor blade dovetail 5 can be
reduced.
[0233] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0234] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 33
[0235] The rotor blade dovetail 5 in the axial flow compressor
according to a thirty-third embodiment of the present invention
will be described with reference to FIG. 35.
[0236] FIG. 35 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirty-third embodiment of the present
invention; on an end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the curved concave surface 9 is formed, which is a cut
surface; on an end surface 5b of the rotor blade dovetail 5 on the
downstream side of the inclined surface 11, which is a flat
surface, the curved concave surface 9b is formed, which is a cut
surface.
[0237] This embodiment described above uses a structure in which
the curved concave surface 9, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
11c of the inclined surface 11, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 11, which is a flat surface, and the curved concave surface
9b, which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of
the working fluid toward the maximum width part 11c of the inclined
surface 11, is also formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 11.
Therefore, a load exerted from the rotor blade 4 can be evened; the
load would otherwise become asymmetric between the forward
direction and reverse direction of the rotational direction of the
rotor blade 4. As a result, high stress exerted on the rotor blade
4 can be reduced.
[0238] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the curved concave surface 9 and curved concave
surface 9b are respectively formed as cut surfaces on the end
surface 5a of the rotor blade dovetail 5 on the upstream side of
the inclined surface 11 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved concave surface 9 and curved
concave surface 9b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced.
[0239] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0240] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 34
[0241] The rotor blade dovetail 5 in the axial flow compressor
according to a thirty-fourth embodiment of the present invention
will be described with reference to FIG. 36.
[0242] FIG. 36 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirty-fourth embodiment of the present
invention; on an end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the curved convex surface 10 is formed, which is a cut
surface;
[0243] on an end surface 5b of the rotor blade dovetail 5 on the
downstream side of the inclined surface 11, which is a flat
surface, the curved convex surface 10b is formed, which is a cut
surface.
[0244] This embodiment described above uses a structure in which
the curved convex surface 10, which is a cut surface formed by
cutting part of the rotor blade dovetail 5 on the upstream side in
the flow direction of a working fluid toward the maximum width part
11c of the inclined surface 11, is formed on the end surface 5a of
the rotor blade dovetail 5 on the upstream side of the inclined
surface 11, which is a flat surface, and the curved convex surface
10b, which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the downstream side in the flow direction of
the working fluid toward the maximum width part 11c of the inclined
surface 11, is also formed on the end surface 5b of the rotor blade
dovetail 5 on the downstream side of the inclined surface 11.
Therefore, a load exerted from the rotor blade 4 can be evened; the
load would otherwise become asymmetric between the forward
direction and reverse direction of the rotational direction of the
rotor blade 4. As a result, high stress exerted on the rotor blade
4 can be reduced.
[0245] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the curved convex surface 10 and curved convex
surface 10b are respectively formed as cut surfaces on the end
surface 5a of the rotor blade dovetail 5 on the upstream side of
the inclined surface 11 and the end surface 5b on its downstream
side, so the weight of the rotor blade dovetail 5 is reduced by the
amount of formation of the curved convex surface 10 and curved
convex surface 10b. This is advantageous in that stress exerted on
the rotor blade dovetail 5 can be reduced.
[0246] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0247] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 34
[0248] The rotor blade dovetail 5 in the axial flow compressor
according to a thirty-fifth embodiment of the present invention
will be described with reference to FIG. 37.
[0249] FIG. 37 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirty-fifth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the concave surface 12 consisting of a plurality of flat
surfaces, each being a cut surface, is formed; on the end surface
5b of the rotor blade dovetail 5 on the downstream side of the
inclined surface 11, which is a flat surface, the concave surface
12b consisting of a plurality of flat surfaces, each being a cut
surface, is formed.
[0250] This embodiment described above uses a structure in which
the concave surface 12 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 11c of the inclined
surface 11, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 11, which
is a flat surface, and the concave surface 12b consisting of a
plurality of flat surfaces, each of which is a cut surface formed
by cutting part of the rotor blade dovetail 5 on the downstream
side in the flow direction of the working fluid toward the maximum
width part 11c of the inclined surface 11, is also formed on the
end surface 5b of the rotor blade dovetail 5 on the downstream side
of the inclined surface 11. Therefore, a load exerted from the
rotor blade 4 can be evened; the load would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade 4. As a result, high
stress exerted on the rotor blade 4 can be reduced.
[0251] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the concave surface 12 and concave surface 12b
consisting of a plurality of flat surfaces are respectively formed
as cut surfaces on the end surface 5a of the rotor blade dovetail 5
on the upstream side of the inclined surface 11 and the end surface
5b on its downstream side, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the concave
surface 12 and concave surface 12b. This is advantageous in that
stress exerted on the rotor blade dovetail 5 can be reduced.
[0252] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0253] According to this embodiment structured as described above,
an axial flow compressor having rotor blade dovetails that reduce
an uneven contact with each wheel dovetail so as to level a load,
exerted from the relevant rotor blade, that would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade and to thereby reduce
high stress exerted on the rotor blade, and a gas turbine, can be
realized.
Embodiment 36
[0254] The rotor blade dovetail 5 in the axial flow compressor
according to a thirty-sixth embodiment of the present invention
will be described with reference to FIG. 38.
[0255] FIG. 38 partially illustrates the rotor blade dovetail 5
that secures the rotor blade 4 included in the axial flow
compressor according to the thirty-sixth embodiment of the present
invention; on the end surface 5a of the rotor blade dovetail 5 on
the upstream side of the inclined surface 11, which is a flat
surface, the convex surface 13 consisting of a plurality of flat
surfaces, each being a cut surface, is formed; on the end surface
5b of the rotor blade dovetail 5 on the downstream side of the
inclined surface 11, which is a flat surface, the convex surface
13b consisting of a plurality of flat surfaces, each being a cut
surface, is formed.
[0256] This embodiment described above uses a structure in which
the convex surface 13 consisting of a plurality of flat surfaces,
each of which is a cut surface formed by cutting part of the rotor
blade dovetail 5 on the upstream side in the flow direction of a
working fluid toward the maximum width part 11c of the inclined
surface 11, is formed on the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 11, which
is a flat surface, and the convex surface 13b consisting of a
plurality of flat surfaces, each of which is a cut surface formed
by cutting part of the rotor blade dovetail 5 on the downstream
side in the flow direction of the working fluid toward the maximum
width part 11c of the inclined surface 11, is also formed on the
end surface 5b of the rotor blade dovetail 5 on the downstream side
of the inclined surface 11. Therefore, a load exerted from the
rotor blade 4 can be evened; the load would otherwise become
asymmetric between the forward direction and reverse direction of
the rotational direction of the rotor blade 4. As a result, high
stress exerted on the rotor blade 4 can be reduced.
[0257] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the convex surface 13 and convex surface 13b
consisting of a plurality of flat surfaces are respectively formed
as cut surfaces on the end surface 5a of the rotor blade dovetail 5
on the upstream side of the inclined surface 11 and the end surface
5b on its downstream side, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the convex
surface 13 and convex surface 13b. This is advantageous in that
stress exerted on the rotor blade dovetail 5 can be reduced.
[0258] With the rotor blade dovetail 5 in the axial flow compressor
in this embodiment, the inclined surface 11 of the rotor blade
dovetail 5 is a flat surface, so the weight of the rotor blade
dovetail 5 is reduced by the amount of formation of the inclined
surface 11 as a flat surface. This is advantageous in that stress
exerted on the rotor blade dovetail 5 can be reduced.
[0259] With the rotor blade dovetail 5 in the axial flow compressor
according to each embodiment of the present invention, any one of
the flat surfaces 6 and 6b, the curved concave surfaces 9 and 9b,
the curved convex surfaces 10 and 10b, the spherical concave
surfaces 15 and 15b, the spherical convex surfaces 16 and 16b, the
concave surfaces 12 and 12b consisting of a plurality of flat
surfaces, and the convex surfaces 13 and 13b consisting of a
plurality of flat surfaces, each of which is a cut surface, is
formed on at least one of the end surface 5a of the rotor blade
dovetail 5 on the upstream side of the inclined surface 7, which is
a curved surface, and the end surface 5b on its downstream side and
the end surface 5a of the rotor blade dovetail 5 on the upstream
side of the inclined surface 11, which is a flat surface, and the
end surface 5b on its downstream side. A range in which the above
cut surfaces are formed on the end surfaces 5a and 5b of the
inclined surfaces 7 and 11 of the rotor blade dovetail 5 is a
portion, of the rotor blade dovetail 5, that corresponds to a range
in which stress at a certain level or higher is exerted from the
rotor blade dovetail 5 to the wheel dovetail 14.
[0260] When an axial flow compressor is started or stopped, stress
exerted from the rotor blade dovetail to the wheel dovetail may be
increased to a designed allowable stress or higher.
[0261] To allow for allowable stress at a certain level or higher
exerted on the wheel dovetail 14, any one of the above cut surfaces
is formed in part of the rotor blade dovetail 5, the part being a
range, of the rotor blade dovetail 5, that corresponds to a range,
in the wheel dovetail 14, in which stress at a certain level or
higher is exerted from the rotor blade dovetail 5 to the wheel
dovetail 14
[0262] To form a cut surface by cutting part of the rotor blade
dovetail 5 of the axial flow compressor 1 in each embodiment of the
present invention described above, the material of the rotor blade
dovetail 5 may be casted so that the rotor blade dovetail 5 is
formed in a state in which it has a certain cut surface in advance.
Alternatively, the rotor blade dovetail 5 may be cut by, for
example, machining or electric discharge machining.
[0263] According to each embodiment, structured as described above,
of the present invention, an axial flow compressor having rotor
blade dovetails that reduce an uneven contact with each wheel
dovetail so as to level a load, exerted from the relevant rotor
blade, that would otherwise become asymmetric between the forward
direction and reverse direction of the rotational direction of the
rotor blade and to thereby reduce high stress exerted on the rotor
blade, and a gas turbine, can be realized.
REFERENCE SIGNS LIST
[0264] 1: compressor [0265] 2: combustor [0266] 3: turbine [0267]
4: rotor blade [0268] 5: rotor blade dovetail [0269] 5a, 5b: end
surface [0270] 6: cut flat surface on upstream side [0271] 6b: cut
flat surface on downstream side [0272] 7: inclined curved surface
of blade dovetail [0273] 7c: maximum width part [0274] 8: wheel
[0275] 9: cut curved concave surface on upstream side [0276] 9b:
cut curved concave surface on downstream side [0277] 10: cut curved
convex surface on upstream side [0278] 10b: cut curved convex
surface on downstream side [0279] 11: inclined surface, which is
flat surface, of blade dovetail [0280] 11c: maximum width part
[0281] 12: cut concave surface consisting of a plurality of flat
surfaces on upstream side [0282] 12b: cut concave surface
consisting of a plurality of flat surfaces on downstream side
[0283] 13: cut convex surface consisting of a plurality of flat
surfaces on upstream side [0284] 13b: cut convex surface consisting
of a plurality of flat surfaces on downstream side [0285] 14: wheel
dovetail [0286] 15: cut spherical concave surface on upstream side
[0287] 15b: cut spherical concave surface on downstream side [0288]
16: cut spherical convex surface on upstream side [0289] 16b: cut
spherical convex surface on downstream side [0290] 18: stator blade
[0291] 19: casing
* * * * *